Una filosofía con rostro humano: Stanley Cavell

Resum: Se trata de una aproximación a la obra del filósofo norteamericano Stanley Cavell, desde dos puntos de vista diferentes:el de la filosofía de cotidiana y el de la teoría estética, para sugerir su obra como germen de una posible teoría de la argumentación política y una aportación al proyecto de reconstrucción de una racionalidad crítica ampliada. Resum: Es tracta d'una aproximació inicial a l'obra del filòsof nord-americà Stanley Cavell, des de dos punts de vista diferents: la filosofia del llenguatge quotidià i la teoria estètica, per a suggerir la seva obra com à germen d'una possible teoria de l'argumentació política i una aportació al projecte de reconstrucció d'una racionalitat crítica ampliada

Phenomenological models of holographic superconductors and hall currents

We study general models of holographic superconductivity parametrized by four arbitrary functions of a neutral scalar field of the bulk theory. The models can accommodate several features of real superconductors, like arbitrary critical temperatures and critical exponents in a certain range, and perhaps impurities or boundary or thickness effects. We find analytical expressions for the critical exponents of the general model and show that they satisfy the Rushbrooke identity. An important subclass of models exhibit second order phase transitions. A study of the specific heat shows that general models can also describe holographic superconductors undergoing first, second and third (or higher) order phase transitions. We discuss how small deformations of the HHH model can lead to the appearance of resonance peaks in the conductivity, which increase in number and become narrower as the temperature is gradually decreased, without the need for tuning mass of the scalar to be close to the Breitenlohner-Freedman bound. Finally, we investigate the inclusion of a generalized ¿theta term¿ producing Hall effect without magnetic field.